1. Field of the Invention
The present invention relates to a surgical clip and forceps for clamping the same.
2. Description of the Prior Art
The microdissection of an aneurism is one of the high-grade operations which have been made possible by a recent advance of surgical technique. However, it is such a difficult operation as to require the greatest possible care and a high technical skill, because the patient is exposed to the danger of excessive bleeding which may becaused by the rupture of the aneurism during the operation. Moreover, stenosis or obstruction of an artery or a capillary vessel in the proximity thereof must not be caused by the clamping of the aneurism. Because of these requirements, it is most common to perform an operation for an aneurism under a microscope of 6 to 20 magnifications. From such minuteness required for performing the operation, various restrictions imposed on the operative instruments are derived.
Conventional clips and forceps pose the following problems:
1. In spite of various shapes and dimensions in which conventional clips are available, conventional forceps do not always allow these clips to be directed in a desired direction according to the position of the aneurism. Consequently, it is sometimes entirely impossible to clamp an aneurism.
2. The thick-bodied end portions of conventional forceps interfere with the visual field to a great degree.
3. A surgeon cannot operate conventional forceps with certainty when the direction in which the two jaws of the forceps have to be moved toward one another for clamping an aneurism differs with the aptitude of his hand. Consequently, it is sometimes impossible to assure the safety of the patient in clamping an aneurism.
Conventional clips widely used by surgeons, especially by brain surgeons, for the arrest of bleeding from an aneurism or a blood vessel or for the treatment of blood vessel obstruction are divided broadly into two groups, one of which includes clips made by bending or curving slender metal wires as shown in FIGS. 1 to 6, while the other includes clips made of long and narrow metal plates as shown in FIG. 7. Conventional clips can also be divided in another way on the basis of structural differences according to the order in which three portions of a clip are arranged: i.e. either a spring eye (or fulcrum) 2, a load-bearing portion 3 and a clamping jaw portion 1 or the load-bearing portion 3, the spring eye 2 and the clamping jaw portion 1. As for the shapes of conventional clips, there are scores of kinds of shapes in addition to those shown in FIGS. 1 to 7. For example, clips having arc-shaped, L-shaped, J-shaped or bayonet-shaped bends are full of variety in dimensions and angles of bend, and are curved or bent in parallel with or perpendicularly to the direction in which the gripping power is applied to the load-bearing portion 3.
Some conventional forceps such as Sugita's, Sano's and FM forceps are used specially to operate the abovedescribed clips in a confined space. As shown in Figs. 8 to 10, a forceps has a holding portion 4, connecting portion (or fulcrum) 5 and grip portion 6. Two jaws constituting the holding portion 4 engage the load-bearing portion 3 of a clip, which is pressed so as to open the clamping jaw portion 1 when the grip portion 6 is clasped. When the surgeon relaxes his hand, the clamping jaw portion 1 of thelip is closed. The clip gets clear of the holding portion 4 when the surgeon further relaxes his hand so as to open the grip portion 6.
In case of a forceps shown in FIG. 8 or 10, two levers constituting the grip portion 6 bear resemblance to tweezers and are connected with each other by a leaf spring. When a pair of binding metals 7 provided on the inside opposite surfaces of these two levers are allowed to engage each other, the clip is left gripped with the clamping jaw portion 1 kept open. In case of a forceps shown in FIG. 9, the levers are provided with rings to be passed over a thumb and a forefinger. When the levers are moved toward or away from each other, a mechanism extending from the connecting portion to the holding portion 4 transmits the movement of the levers to one or both of the jaws constituting the holding portion 4 and opens or closes the holding portion 4.
In case of a forceps shown in FIG. 8, 10, 11 or 12, grooves 4' are provided in the inside opposite surfaces of the end portions of the jaws constituting the holding portion 4. The shape of the grooves 4' is substantially complementary to the curvature of the load-bearing portion 3 of a clip. With this type of forceps, however, the clip can be directed only in a sense which is determined by the direction of the grooves 4'. In order to eliminate this drawback, several types of forceps including two types of Sano's forceps have already been developed. One type of Sano's forceps can be bent both in the holding portion 4 and in the grip portion 6 as shown in FIG. 15 so that the direction of the clip can be adjusted to the position of an aneurism. The other type of Sano's forceps (not shown) can be bent only in the grip portion 6, while rotors 4" are provided in the holding portion 4. However, Sano's forceps, especially the former type thereof, has the disadvantages that the thick-bodied end portion interferes with the visual field in an operation performed under a microscope of 6 to 20 magnifications and that it is difficult to subject the sense of the clip to fine adjustment. In order to cover up these disadvantages, surgeons are required to keep a large number of variously shaped clips and forceps ready for their hands.
In case of a forceps shown in FIG. 9, 13 or 14, rotors 4" provided on the inside opposite surfaces of the end portions of the jaws constituting the holding portion 4 have a U-shaped section so as to adapt themselves for supporting a clip in such a manner that the load-bearing portion 3 of the clip is flanked on both sides by the legs of each rotor 4". Although this forceps is much better than the one shown in FIG. 8, 10, 11 or 12 in that the clip can be directed in any sense, the provision of the rotors 4" makes the holding portion 4 more bulky and causes a grave hindrance to the performance of an operation because of an obstructed visual field. Another trouble is that, when a clip is to be removed from an aneurism, the sense of the rotors 4" has to be mated with the direction in which the clip has been clamping the aneurism. This is troublesome all the more because each rotor 4" constituting a pair rotates separately. When an emergency such as the rupture of an aneurism occurs during an operation, several seconds required for this troublesome mating procedure may possibly cause a delay in clamping an artery and thereby lead to an irrevocable result.
Still another trouble is derived from a mechanism common to all the conventional forceps. Although they are different from one another in the shape of the grip portion 6 as shown in FIGS. 8 to 10, all of them have the same mechanism in that the movement of the grip portion 6 is transmitted to the holding portion 4 through the connecting portion (or fulcrum) 5. Therefore, when a clip is gripped by one of these conventional forceps, two jaws constituting the clamping jaw portion 1 of the clip move toward and away from one another in the direction parallel with the movement of two levers constituting the grip portion 6. When an aneurism is found on an artery running lengthwise in a field of operation, the clamping jaw portion 1 of the clip to be positioned on the neck of this aneurism has to be opened in the direction parallel with the artery and, for this purpose, two levers constituting the grip portion 6 of the forceps have to be moved in the lengthwise direction in the field of operation.